Improvement of the electrical properties of PECVD silicon oxide using high-density and low-ion-energy plasma post-treatment

摘要

We have studied the electrical properties of the high-quality plasma enhanced chemical vapor deposition (PECVD) silicon oxide deposited by high-density and low-ion-energy plasma at 400 degrees C and the effect of the plasma post-treatment on its electrical properties. Analysis of the gate voltage shift during constant current stress and the high-frequency C-V characteristics indicate that the bulk electron trap and the interface charge densities are reduced from 3.2 +/- 0.1 x 10(18) cm(-3) and 1.5 +/- 0.1 x 10(11) cm(-2) to 1.5 +/- 0.2 x 10(18) cm(-3) and 4 +/- 0.3 x 10(10) cm(-2) by the high-density and low-ion-energy plasma post-treatment, respectively. In addition, the capture cross-section of the bulk trap is 2.6 +/- 0.2 x 10(-11) cm(2). The silicon oxide films deposited by the high-density low-ion-energy plasma and plasma post-treatment exhibit excellent properties, e.g., high-breakdown electric field (> 12 MV/cm) and high charge-to-breakdown. These properties of the films have approached those of high-temperature thermal oxide films. (c) 2005 Elsevier B.V. All rights reserved.